Investigators say Knox's DNAwas found on the handle of the knife and Kercher's DNA on the blade. Lawyers for both defendants have contested these findings, saying the amount of DNA found on the blade is too small to be reliable; they also say that the knife in question is too big to have caused some of the cuts in the victim's neck.

A panel of three forensic experts appointed in February 2008 by a previous judge involved in the investigation were called to testify on Saturday about their findings regarding the time and cause of death, and sexual assault.

Forensic expert Mariano Cingolani, who had focused on the cause of death, told the court today that kitchen knife in question was "not absolutely incompatible" with the wounds in the victim's neck, but said that it would have been difficult for one of the smaller of the three cuts to have been made by a knife with a 6½-inch blade such as evidence item 36, the kitchen knife.

But, "considering the dynamic nature of events," Cingolani said his team felt it could not completely exclude the knife as the murder weapon. He added that "many other knives are much more compatible with that wound than that knife."

Kercher Had 'Sexual Activity' Close to Time of Death, but Was It Rape?

Another expert, Giancarlo Umani Ronchi, told the court that his impression, from examining autopsy results and evidence regarding the case, was that there was "an escalation in the injuries" to Meredith Kercher.

"There was an evolution in the injuries, from those of a modest entity to those that caused death," said Ronchi, referring to three cuts to Kercher's throat, which range from a depth of less than an inch for the smallest cut to the 3 inches of the deepest gash.

The cause of Kercher's death, which forensic expert Cingolani felt probably took place in a matter of minutes, is to be attributed to a combination of strangulation, suffocation and loss of blood. The injuries to Kercher's throat, which include a large gash on the left side of her neck, caused blood to enter her lungs, and bruises on her neck indicate she was strangled as well.

The third expert of the day, Anna Aprile, was asked to explain whether it could be established if Kercher was raped before being killed. Aprile told the judge and jury that Kercher "had sexual activity close to the time of death" based on the autopsy results, but that she could not say whether that activity was consensual or not.